v0.21.1

Features

• Media — Image, video, audio, and file blocks can now be restricted to upload-only or link-only via configuration, so consumers can offer a single source instead of always exposing both.

Maintenance

• Media — Deduped MediaSource into a single shared type across the media tools.
• Docs — Documented the audio block tool, and added upload-only and link-only empty states to the playground gallery.